Combine the dark brown sugar and filtered water in a small saucepan over medium heat, stirring until the sugar crystals dissolve completely.

Simmer the syrup gently for three minutes until a cohesive molasses glaze forms, then remove from heat and cool down completely to room temperature.

Grind the blonde roast coffee beans to a fine espresso consistency seconds before brewing to maximize volatile flavor retention.

Extract two shots of concentrated espresso using an espresso machine or Moka pot, aiming for sixty milliliters total volume.

Add one tablespoon of the cooled brown sugar syrup concentrate into the base of a stainless steel cocktail shaker.

Pour the hot freshly extracted espresso shots directly over the syrup base inside the cocktail shaker.

Fill the shaker container completely to the brim with large solid dense ice cubes to manage thermal mass and control dilution.

Add a generous pinch of ground Ceylon cinnamon directly into the ice and espresso mixture matrix for aromatic infusion.

Seal the shaker caps tightly and shake vigorously with high kinetic force for fifteen full seconds to create stable macrofoam aeration.

Immediately strain the chilled foamy espresso solution along with the ice cubes into a tall serving glass tumbler.

Pour cold barista edition oat milk slowly into the center of the glass, allowing it to cascade through the espresso foam and create beautiful marbled layers.

Serve immediately without stirring to preserve the visual layering and foam structure.